I got in during one of the earlier waves of invites. Unfortunately, it didn't keep my interest beyond the intro and unlocking each deck type. I used to play the Pokemon TCG competitively, and I feel that Hearth Stone is still too unrefined as of yet. Once it goes live I'll look at it again, but I don't believe that it'll take away from my interest in Diablo 3.
_________________Free hugs (>^^)>
My SNS at it's best: Silmeria